The demand function for good Xsi nI Q: $=$ a $+$ b nI Px$+$c nI M et$,$ where rP si the price of good Xand Mis income. Least squares regression reveals that $=7\mathrm{.}42,6=-21\mathrm{.}8,$ and $^=0\mathrm{.}34.$

$.$a fI M$=55,000$ and P$,=4\mathrm{.}39,$ compute the own price elasticity of demand based on these estimates. Determine whether demand si elastic or inelastic.

b$.$ fI M$=55,000$ and P$,=4\mathrm{.}39,$ compute hte income elasticity of demand based on these estimates. Determine whether Xsi a normal or inferior